Leachability and Toxicity of Hydrocarbons, Metals and Salt Contamination from Flare Pit Soil

Although composite chemical analyses, such as total petroleumhydrocarbons and total metals, are often used to assess theextent of contamination at an industrial site, it is difficultto relate chemical analyses to the environmental andtoxicological effects of soil contamination. Since toxicity isrelated to contaminant bioavailability and solubility,identification and quantification of leachable contaminantsshould provide an indication of the environmental hazard of the site contaminants. Experiments were performed to determine theleachability and toxicity of contaminants from a flare pit soilwhich was extensively contaminated with hydrocarbons, metals andsalt. Toxicity bioassays included earthworm mortality(Lumbricus terrestris), seed germination and root elongation(Lactuca sativa and Panicum miliaceum L.),algal growth inhibition (Selenastrum capricornutum) andbacterial luminescence inhibition (Pseudomonasfluorescens). Although this soil would require remediationaccording to chemically based soil criteria, neither the contaminated soil nor leachate generated from the contaminated soil were particularly toxic.